Explain what the swap rate curve is, and the reasons and ways that market participants rely on it when valuing instruments

The swap rate curve plots the fixed rates at which dealers swap fixed payments for a floating reference rate across maturities. Many participants prefer it to the government curve as a benchmark because it is quoted in a deep, liquid market at many maturities, it is not distorted by government issuance or scarcity of particular bonds, and it reflects the credit risk of the banks whose funding costs it mirrors. Banks and corporate treasurers use it to value floating-rate liabilities, to price derivatives and to quote bond spreads, notably the I-spread, which is a bond's yield minus the swap rate of the same maturity. Do not confuse the I-spread with the G-spread.